ANY IDEAS ON WHAT’S CAUSING THIS

[MegaFan]

Compare the angle in the video brass deflection to the point of impact on your brass. Looks like a good fit in location to your strike area.

 

[rosewood]

I have seen this dent from several different ARs. I believe it is common and have never worried about it. Just resize and move on.

It does indeed look like the back edge of the ejection port. Mystery solved!

Rosewood

 

[xlr8ngn]

Mark a line down the side of your brass with a sharpie and drop one in the chamber. It will help you narrow down where the dent is coming from.

 

[Paxdad]

I use a trimmed to size piece of adhesive Velcro on my deflector fix this cause. I use the looop or fuzzy piece.

 

[Putnambuck]

I've figured it out thanks to my fellow ODTR'S.....it was in fact the shell deflector, got to looking at it closer and can see on the edge of it where the shells have been hitting. I'm not going to worry about it now that I know that's all it is although the adhesive velcro trick might keep it from doing it as bad.
I appreciate all the input & advice.......thanks fellas!

 

[QRU Armory]

case deflector for sure. You should see the brass marks

 

[Putnambuck]

case deflector for sure. You should see the brass marks

Yep, sure can

 

[SamSamson]

I had a Sig 556 XI that did that to most of the brass that was shot threw it. I read somewhere that someone glued a piece of velcro on the deflector to help stop it.

 

[Cammoarcher]

Have you noticed different charges deflect differently? Speed it up or slower charge as long as you aren't maxed out.